Strombolian Eruptions

Activity at Anak Krakatau in November 2007 was characterized by minor, but ash-rich strombolian eruptions ocurring every one to three minutes, and occasionally longer periods with no eruptive activity after which more powerful vulcanian explosions happened (which are covered on other pages).

Strombolian Eruptions
At dusk an ash-rich eruption fills the active vent with ash and incandescent bombs. The summit crater is on the right
Strombolian Eruptions
A few moments later bombs roll down the cone's southern slope kicking up a lot of dust. Meanwhile the ash column rises.
Strombolian Eruptions
Often lightning occurs within the ash column caused by turbulence and frictional effects between ash particles.
Strombolian Eruptions
The ash column rises and creates a lot of turbulence. Bombs only become visible once they come out of the dense ash cloud.
Strombolian Eruptions
Sometimes the ash column reaches high atmospheric layers, where winds take different directions.
Strombolian Eruptions
This zoom on the active vent shows details of its interior. Fumaroles are visible in the summit crater (top).
Strombolian Eruptions
In the evening of 22nd November, fresh magma is rising within the conduit. The spectacular eruptions reminding us of Etna.
Strombolian Eruptions
Sometimes the incandescent bombs are bright enough to cause remarkable reflections in the calm sea.
Strombolian Eruptions
The ash column rises several kilometers into the sky, higher than the cumulus clouds.
Strombolian Eruptions
Fishermen observe the "volcanic fireworks" as very fresh magma explodes inside the vent.
Strombolian Eruptions
On other evenings, the magma is less hot. Therefore the bombs are of a dull red color.
Strombolian Eruptions
Thunderstorms over Sumatra, far to northwest (note lightning on the left).
Photos by Marco Fulle, taken from Rakata Island from 21 to 24 Nov 2007, about 5 km SSE of Anak Krakatau. Photos taken with 28mm, 50mm, 135mm and 300mm lenses and digicam (to be multiplied by 1.5 to obtain the equivalent focal length on 24x36 film).